POTATO INSECTS 



145 



had also been slow and the beetles did not a})pear in eentral 

 Louisiana until about the same date. The potato beetle is 

 now generally distributed east of the Roeky Mountains from 

 Montana to New Brunswick and Nova Scotia and southward 

 to northern Florida. It also occurs in New Mexico and Ari- 

 zona and in Idaho, Washington and Alberta. Where the 

 potato is not available for food, the beetles will sometimes 

 attack eggplant (Fig. 81), tomato, pepper and even tobacco. 

 Ground cherry, thorn apple, hen!)ane, Jamestown weed, horse 

 nettle, belladonna and petunia also serve to carry the beetles 

 through periods of scarcity. 



The potato beetle hibernates as an adult sometimes under 

 rubbish but more frequently in the soil at a depth of several 

 inches. The beetles emerge 

 from their winter quarters in 

 the spring just before early 

 planted potatoes come up. 

 At this time they will feed on 

 pieces of seed potatoes left on 

 the surface and will some- 

 times dig into the soil in 

 search of the tender sprouts. 

 They feed for a time on the 

 tender foliage and then, after 



pairing, deposit their eggs on end in masses on the under- 

 side of the leaves (Fig. 82). Each mass contains from four 

 or five to nearly seventy eggs with an average of about twenty- 

 five. The egg is about Yt inch in length, elongate oval and 

 orange in color, with the surface smooth and shining. The 

 egg is glued to the leaf with a small mass of orange-colored 

 material. The female is capable of laying from 200 to over 

 1800 eggs with a probable average of 400 or 500. The eggs 

 do not ripen continuously })ut in successive batches ; all the 

 eggs which ripen at a given time may be deposited in one or 



Fig. 82. — The Colorado IX. la to iM'oilo, 

 e^gs and newly haUdied larvai 

 (enlarged). 



